System of control



R. E. HELLMUND.

SYSTEM OF CONTROL.

APPLICATION FILED sen. z, 1917.

Patented Dec. 14, 1920.

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INVENTOR Rudolf E Hal/mund WITNESSES: 7/

ATTORNEY H. t. HtLLMuwu.

SYSTEM OF CONTROL.

APPLICATION mzo SEPT. 7. ISII.

Pamnted D60. 14, 1920.

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A'ILTORNEY UNITED STATES PATENT OFFICE.

RUDOLF E. HELLMUND, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR ,TO WESTING-HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

SYSTEM OF CONTROL.

Specification of Letters Patent.

Patented Dec. 14, 1920.

Application filed September7, 1917. Serial No; 190,134.

7'0 all whom it may concern:

Be it known that I, RUDOLF E. HELLMUNO, a citizen of theGerman Empire,and a resident of Swissvale, in the county of Allegheny and State ofPennsylvania, have mvented a new and useful Improvement in Systems ofControl. of which the following changeable, dependent upon operatingconis a specification.

My invention relates to systems of control and especially to systems ofthe booster type wherein an auxiliary-machine armature is employed forthe purpose of regulating the rain-machine operation in lieu of thecustomarily employed main-circuit resistors.

Curious systems of the above-indicated character have heretofore beenproposed, but more or less difliculty has been encountered in theiroperation by reason of surges of current caused by supply-circuitvoltage fluctuations or by flash-over conditions caused by the use ofshunt-field windings in the booster machines.

The object of my present invention is to provide a relatively simple andreliable system of the above-indicated character where in flash-overconditions and the liability of heavy current surges are substantiallyobviated.

My invention may be best understood by reference to the accompanyingdrawings wherein Figure l is a diagrammatic View or the main circuits ofa system of control cnihmlying the invention; Fig. 2 is a diagrammaticview of the auxiliary governing circuits for the system that is shown inFig. 1; and Fig. 3 is a sequence chart, of well-known form, serving toindicate the preferred order of operation of the various switches duringboth acceleration and regeneration. Referring to Fig. 1 of the drawings,the system shown comprises supply-circuit conductors Trolley and Ground;a main dynanurelectric machine having a commutaor-type armature A1 and afield winding FL of the series type; a motor-generator set 155 of thebooster type; a plurality of clectrically-controlled switches LS and 1to 11, inclusive; a normal-voltage relay device 12; an over-voltagerelay device 13; and a plurality of variable resistors R1 to R4,inclusive, that are associated with the various machine circuits, in amanner to be set forth.

The motor-generator set 15 comprises a driving or motor armature 16which is mounted upon a shaft 17 carrying also an exciting armature 18and a generator armature 19. The terms motor-armature and generatorarmature are chosen for purposes of distinction, although the characterof action of such armature is interditions Field windings 20,21 and 22are provided for the respective auxiliary armatures, such field windingsbeing energized partially or wholly from the exciting armature 18, assubsequently traced in detail.

The shunt field winding 21 for the exciting armature 18 is connected incircuit with a variable resistor R4, whereby the exciting voltage may beinitially adjusted to satisfactorily meet operating conditions. Ashereinafter more fully described, the auxiliary motor armature 16 isconnected in series relation with the main machine, while the auxiliarygenerator armature 19 is connected inparallel relation thereto.

The normal-voltage relay device 12 comprises an actuating coil 25 thatis connected across the exciting armature 18 for the purpose ofadjusting the position of the customary magnetizable core member, towhich is attached a plurality of bridging contact members 26 and 27 forclosing certain auxiliary circuits to be described in connection withFig. 2. The relay device 12 is raised to its upper or circuit-closingposition only when the voltage of the excitmg'armature 18 equals orexceeds a predetermined relatively high value.

The over-voltage relay 13 comprises an actuating coil 28 and a bridgingcontact member 29 which normally occupies its lower or circuit-closingposition and is raised therefrom only under conditions of excessivecombined voltages of the main armature and the auxiliary armature 16.

Referring to Fig. 2, the auxiliary governing system shown comprises theactuating 0011s of the several switches that are shown in Fig. 1 and thebridging contact members of the relay devices 12 and 13, together with amaster controller MC having a plu rality of operative positions a to f,inclusive, corresponding to acceleration, and a to f, inclusive,corresponding to regeneration; and a battery B or other suitable sourceof cnerg 1 for the auxiliary system.

Assuming that it is desired to effect acceleration of the main machine,the master controller MC is actuated to its initial acceleratingpositionia, whereby a circuit is established from the positive terminalof the battery B through conductor 40; control fingers 41 and 42, whichare bridged by fingers 54 and 55; and conductors 56 and 57,

to the actuating coils of the switches 11 and 2, respectively,, wherebysuch switches are initially closed topartially short-circuit theresistor R1 and thereby provide the maximum excitation for the auxiliaryseries-reiated armature 16, under starting conditions of the main motor,for a purpose to be pointed out. Onthe other hand, the switches 4 and 5initially remain open to suitably weaken the field excitation for theauxiliary parallel-related generator armature 19.

A further circuit is initially established from the contact segment 43through control finger 58, conductor 59 and the actuating coil oftheswitch 7 to the negative conductor 47 I The three auxiliary machines arethus initially connected inseries relation across the supply circuit,andthe booster set is gradually brought up to speed, the field windings20 and 22 bein thus series-excited to produce the desired initial Voltae of theexciting armature 18 by means 0 the shunt-excited field winding21.

When such initial voltage has been attained, a further auxiliary circuitis completed from the contact segment 43 through control finger 48,conductor 49, bridging contact member 26 of the normal-voltage relaydevice 12, which now occupies its upper position, conductor 50, and theactuating coil of the switch 3 to the ne ativc conductor 47. A similarcircuit is continued from the contact segment43 through control fin er51, conductor 52, bridging contact mem er 27 of the relay 12, in itsupper position, and

conductor 53, to the actuating coil ofthe switch 6. The field windings20 and 22 for the auxiliary armatures 16 and 19 are thus energized fromthe exciting armature 18. in accordance with circuits about to betraced.

After the booster set attains its full operating condition, the mainmachine is gradually accelerated, either as a straight series motor, byleaving the switch 11 in its illustrated open condition, or by closingthe switch 11 to provide additional excitation' for the main fieldwindin F1. Such initial closure of the switch 11, if desired, may hareadily accomplished by manually closing switch 60 (Fig. 2) whichconnects the positively energized conductor .44 to'the actuating coil ofthe switch 11.

he various main'circuits that have been completed in the previouslydescribed manner may be set forth as follows:

The-main machine circuit, indicated by solid arrows, is established fromthe lrollcy through conductor 65, line switch LS, conductor 66,auxiliary driving armature 1(3, junction-point 67,conductor 68,switches 1. and 2, which partially short-circuit the rcsistor R1,"switch3, conductors 69, and 71, main-field winding F1, junction-point 72,mainnrrhature A1, and conductors 73 and 74, to the negativesupply-circuit conductor Ground.

One of the exciting circuits, indicated by the dotted arrows, isestablished from the positive terminal of the exciting armature 18,through conductors 75, 76, 70 and (3.). switches 3, 2 and 1, conductors8 and 7?, auxiliary field winding 20, switch 7, and conductor 78, to ajunctionpoint 79 A socond exciting circuit is completed from theconductor 69 through conductor 80, auxiliary field winding 22,conductors 81 and 82, switch 6, resistor R2, and conductor 83 to thejunction-point 79, whence a common circuit is completed throughconductor 84 to the negative terminal of the exciting armw ture 18.

Another circuit is established from the positive terminal of thegenerator armature 19, through conductors 85 and 82 to thepreviously-mcntioned junction-point 79, where the circuit may divide,dependent upon the closed or open condition of the switch 1.1. lVith theswitch closed, the circuit traverses the resistor R3 and the switch 11to the junc tion-point 72. \Vith the switch open, the circuit iscontinued through conductor 84-, exciting armature 18, conductors 75, 76and 71, main field winding F1 and junctionpoint 72, whence circuit iscompleted through main armatureril, and conductors 73, 86 and 87, to thenegative terminal oi the generator armature 19.

It will be seen that the auxiliary driving armature 16 is thus connectedin series relation with the main machine to perform a function similarto that of the familiar accelerating resistors, while the generatorarmature 19 is connected in parallel relation to the main machine tofurnish a portion of the accelerating current therefor, the fieldwindings for the two auxiliary arma tures 16 and 19 being energized bythe exciting armature 18.

To further accelerate the main machine, the master controller may beactuated to its second position b, whereupon the contact segment 43engages control finger 90, whence circuit is continued through conductor91 lull lll l ill:

and the actuating coil of the switch 4, to the negative conductor 47. Asection of the resistor R2 is thus short-circuited to correspondinglyincrease the voltage of the generator armature 19 and thus further raisethe voltage impressed upon the main armature A1.

By actuating the master controller to its position 0, the contactsegment 43 first becomes disengaged from the control finger 55 to eflectthe opening of the switch 2 and then makes contact with control finger92 to complete a circuit therefrom through conductor 93 and theactuating coil of the switch 5. A portion of the resistor R1 is thusincluded in circuit by the opening of the switch 2 to weaken theexcitation of the auxiliary field winding 20, thereby de creasing thevoltage of the auxiliary armature 16 and correspondingly increasing theportion of supply-circuit voltage that is delivered to the main armatureA1, and, secondly, short-circuitin the remainin scction of the resistor1 1 2 to correspondingly strengthen the field excitation for the g6l1erator armature 19 and thus impress a larger voltage upon the mainmachine. In position d of the master controller, the switch 1 is openedby reason of the disengagement of contact segment 43 and control finger54 to further weaken the excitation of the auxiliary driving armature 16and efi ect another QCCBlGIatIDg step of the main machine.

In transition position 6, the auxiliary driving armature 16 is excludedfrom circuit by effecting the disengagement of the contact segment 43and control finger 58, thus opening the switch 7. In position f, a newcircuit is established from the contact segment 43 through controlfinger 94, conductor 95, and the actuating coil of the switch 8, therebydirectly connecting maincircuit conductors 66 and 70. The booster set isthen driven from the supply circuit by the generator armature 19, nowacting as a motor, the armature 16 remaining inactive to reduce theoperating losses of the system, while the full supply-circuit voltage isimpressed upon the mam machine.

The inherent regulating features of my system, whereby surges ofaccelerating current are prevented, will now be set forth. From theprevious descri tion, it will be observed that the resistor 2 carries,in the same direction, the currents of both the enerator armature 19 andof the excitingeld winding 22. Consequently, any incipient increase ineither of these currents, caused by an upward fluctuation ofsupply-circuit voltage, for example, to increase the speed of thebooster set, will correspondingly increase the voltage .drop across theresistor R2 and thus weaken the excitation of the field winding 22 whichis connected in series-circuit relation therewith. The voltage of thegenerator armature 19 is thus reduced to impress a decreased voltageupon the main machine and thereby counteract the incipient rise ofaccelerating current.

Furthermore, current from the auxiliary driving armature l6 traversesthe resistor R1 in a direction opposite to the current that flowsthrough the resistor from the exciting armature 18. Consequently, anyincrease of accelerating current in the auxiliary driving armature 16will decrease the voltage drop across the resistor R1 by reason of thedifferential relation of the currents just mentioned and thus increasethe excitation of the auxiliary field winding 20.

Such action will correspondingly augment the counter-electromotive forceof the driving armature 16 and thus again counteract the imgendingincrease of accelerating current. t will be understood that the converse actions inherently occur in the auxiliary armatures 16 and 19 uponan incipient decrease of accelerating current. In this way, heavy surgesof main-machine current during the accelerating period are inherentlyprevented.

To efl'ect regenerative operation of the main machine under suitablespeed conditions thereof, the master controller may be actuated from itsintermediate ofi' position to the initial regenerative position a.Switches LS, 3, 4, 5, 6 and 8 are closed in accordance with thepreviously described circuits, a contact segment 96 of the mastercontroller being substituted for the previously mentioned contactsegment 43 during the regenerative period.

A new circuit is established from the contact segment 96, throughcontrol finger 97 and conductor 98, to the actuating coil of the switch11, whereby an auxiliary excitation circuit is established from thepositive terminal of the exciting armature 18, through conductors 75, 76and 71, main field winding F1, junction-point 72, switch 11, resistorR3, junction-point 79, and conductor 84 to the negative terminal of theexciting armature. Themain machine is thus initially connected to thesupply circuit through the switches 8 and LS.

By moving the master controller to position I), one new circuit isestablished from the contact segment 96, through control finger 100 andconductor 102, to the actuating coil of the switch 9, and a secondcircuit is subsequently completed from the contact segment 96, throughcontrol finger 103 and conductor 104, to the actuating coil of theswitch 10. The resistor R3 is thus partially short-circuited to increasethe main field excitation.

In position 0, the contact segment 96 first is disengaged from thecontrol finger 94, to open the switch 8, and then makes contact with thecontrol finger 58 to close the, switch 7 and complete the seriesconnection of the auxiliary drivin armature 16 with the main machine. lithout tracin in detail, the various main follows the opposite directionfrom that indicated by the solid arrows. t

In the present instance, however, .switches 1 and 2 are initially opento excite a relatively small voltage in the auxiliary armature 16, whilethe switches 4. and 5 are closed to produce a relatively high voltage inthe generator armature 19, thus producing the opposite effect from thatinitially attained during acceleration.

To compensate for the gradual, decrease of vehicle speed during theretardation period, the master controller may be moved to its position dto energize the control, finger 54 and thereby close the switch 1 toshort-circuit a section of the resistor R1 and correspondingly increasethe voltage of the series-related auxiliary armature 16, which thusabsorbs a greater portion of the supply-circuit voltage and permits themain machine to regenerate at a voltage lower than that of the supplycircuit.

In position e, the control finger 55 is like wise energized to close theswitch 2 for a similar purpose, tact segment 96 becomes disengaged fromthe control finger 92 to effect the openin of the switch 5 and thuscorrespondingly ecrease the excitation of the parallel-related auxili-.ary armature 19. In the final position f, a similar action occurs withrespect to the switch 4, whereby the entire resistor R2 is included incircuit during the lowest speed range of the regenerating main machine.

\Vithout a detailed description, it will be understood that the inherentaction of the resistors B1 and R2, during the regenerative period,serves to prevent sudden vari-- ations of main-machine current, althoughthe currents from the auxiliary armatures 16 and 19 traverse the alliedresistors R1 and R2 in the opposite direction from that taken duringacceleration; that is, the exciting current from the auxiliary armature18 and the current from the auxiliary driving armature 16 traverse theresistor R1 in the same direction, while the currents from the excitingarmature 18 and the generator armature 19 traverse the resistor R2 inopposite directions.

Furthermore, the active portion of the resistor R3 effects an inherentregulating action of a similar nature. Since the mainarmature currentand the main-field-winding current traverse the resistor R3 in the samedirection during regeneration, an incipient increase of regeneratedcurrent correspondingly increases the voltage drop circuits, itwill beunderstood that the regenerative current and, in addition, theconsisters R1 and.

'rangements, such as p a relatively simple system i for inherentlypreventing sudden variations of main-machine current during eitheracceleration or regeneration, and furthermore, flash-over difficultiesare obviated bv, reason of ithewelimination of shunt fiel windings fromthe auxiliary drivingarmature and the generator armature 16 and 1 9,respectively. z i

It will be appreciatedthat, by suitable design and arrangement of parts,any desired degree of compounding may be imposed upon the main armature;that is, any desired degree of shunt operating characteristic may beprovided. Furthermore, in lieu of the single main machine that I haveillustrated, for purposes of simplicity and elearness, two or more mainmachines may be utilized, and series-parallel control thereof may beemployed, as set forth, for example, in my coending application SerialNo. 71,198, filed l anuary 10, 1916.

Moreover, it will be evident that the rel 12 may readily be connected mcircuit to carry the sum or the difierence of certain combinations ofauxiliary-armature and auxiliary-field winding currents other than thoseillustrated; that is, the aux iliary-driving-machine andauxiliary-generating-machine armature and field-winding circuits may beinterconnected in various ways.

I desire it to be understood that, by the statement in the accompanyingclaims, an auxiliary armature winding connected in parallel-circuitrelation to the main machine, I do not restrict myself to a direct shuntconnection of such auxiliary armature across the main machine, butequivalent arconnection of the auxiliary armature across the supplcircuit, are also intended to be covered. Ciinsequentl I do not desireto be restricted to the speci c circuit connections or arrangement ofparts herein set forth, as various modifications thereof may be effectedwithout departing from the spirit and scope of the invention. I desire,therefore, that only such limitations shall be imposed as are indicatedin the appended claims.

claim as my invention:

1. Ina system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings respectivelconnected in series-circuit relation with, an in parallel-circuitrelation to said main machine, means for exciting said auxiliaryarmatures, and a translating device connected in circuit to carry acombination of the auxiliary arn'iature currents and the auxiliaryexciting currents.

2. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings respectivelyconnected n 'i *s-rircuit rela tion with, and in parallet .1: nitrelation to said main machine, means for exciting said auxiliaryarmatures, and a plurality of translating LlCVl es connected in circuitto respectively carry the sum and the difference of certain of theauxiliary-armature currents and auxiliary exciting currents.

3. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings respectivelyconnected in series-circuit relation with, and in parallel-circuitrelation to said main machine, a plurality of field windings for saidauxiliary armatures, a source of energy for exciting said fieldwindings, and a plurality of resistors res iectiveiy connected incircuits common to the auxiliary armatures and the auxiliary fieldwindings.

l. In a system of control. the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings respectivelyconnected in series-circuit relation with, and in parallel-circuitrelation to said main machine, a plurality of field windings for saidauxiliary armatures, a source of energy for exciting said fieldwindings, a resistor connected in rircuit with the seriesrelatedauxiliary machine to carry the difference of the correspondingari'nature and field-winding currents, and a second resistor connectedin rircuit with the parallehr lated auxiliary machine to carry the sumof the corresponding armature and field-winding currents.

5. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings respectivelyconnected in series-circuit relation with, and in parallel-circuitrelation to said main machine, means for exciting said auxiliaryarmatures, and means associated with the respective auxiliary machinesfor inherently counteracting variations of the portion of main-machinecurrent that tra erscs each auxiliary machine.

6. In a system of control, the combination with a main dynamo-electricmachine and a supply circuit therefor, of a plurality of auxiliaryarmature windings respectively connected in series-circuit relationwith, and in parallel-circuit relation to said main machine, alow-voltage source of energ and a single field winding for each of saidauxiliary armatures excited from said source.

7. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings respectivelyconnected in series-circuit relation With, and in parallel-circuitrelation to said main machine, a source of energy, and a single fieldwinding for each auxiliary armature dependent for effective excitationpartially upon said source and partially upon the corresponding armaturecurrents.

8. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings one of which isconnected in series-circuit relation with said main machine, means forexciting said auxiliary armatures, and a translating device connected incircuit to carry a combination of the auxiliary armature currents andthe auxiliary exciting currents.

9. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature windings one of which isconnected in series-circuit relation with said main machine, means forexciting said auxiliary armatures, and a plurality of translatingdevices connected in circuit to respectively carry the sum and thedifference of certain of the auxiliary-armature currents and auxiliaryexciting currents.

10. In a system of control, the combination with a main dynamo-electricmachine, of a plurality of auxiliary armature wind ings one of which isconnected in seric. circuit relation with said main machine, anauxiliary source of energy independent of said series-circuit, and asingle field winding for at least one of the auxiliary armaturesdependent for effective excitation partially upon said auxiliary sourceand par tially upon the corresponding armature current.

11. In a system of control, the combination with a main dynamo-electricmachine. of a plurality of auxiliary armature Wind ings, one of which isconnected in seriescircuit relation with said main machine, an auxiliarysource of energy independent of said series circuit, and a single fieldwind ing for at least one of the auxiliary armatures dependent foreffective excitation partially upon said auxiliary source and partiallyupon the load of the system.

In testimony whereof, I have hereunto subscribed my name this 23rd dayof Am gust, 1917.

RUDOLF E. HELLMU N D.

